Cryobiopsy versus fine-needle aspiration for shape-sensing robotic-assisted sampling of small lung nodules

Introduction: Shape-sensing Robotic-assisted Bronchoscopy (ssRAB) has emerged as a promising tool for improved performance when sampling pulmonary nodules (PPN). Previous studies suggest that the 1.1 mm cryoprobe is as effective compared to fine needle aspiration (FNA), for different lesions sizes. We aim to compare the 1.1 mm cryoprobe performance to FNA for sampling PPN < 20 mm with ssRAB.

Material and methods: We conducted a retrospective cohort study from November 2022 to February 2024 of patients who underwent ssRAB with cryobiopsy for evaluation of PPN. We compared the diagnostic yield and sensitivity for malignancy of cryobiopsy and FNA for the same PPN. Descriptive statistical analysis was conducted using the McNemar's Test and Comparison of proportion. Multivariate logistic regression assessed the impact of PPN characteristics on the yield of each tool.

Results: We included 256 patients, with a combined 284 procedures, and 324 nodules sampled. The median maximum and minimum nodule size was 1.6 cm (IQR 1.17-2.4) and 1.17 cm (IQR 0.86-1.7) respectively. The overall ssRAB diagnostic yield was 93.8 % and sensitivity for malignancy was 97.5 %. Cryobiopsy had a diagnostic yield of 92 % and sensitivity of 96 %, FNA had a 70.4 % and 79.29 % respectively (P < 0.001). Cryobiopsy had a significantly higher performance compared to FNA across the analyzed categories (P < 0.05), except for the sensitivity of mixed-type lesions (P = 0.11). PPN < 10 mm and ≥ 10 mm - <15 mm sampled with FNA, had lower odds of achieving a diagnosis compared to the ≥ 20 mm group (OR = 0.305 IC95%: 0.142-0.65, p < 0.001; OR = 0.497 IC95%: 0.263-0.939, p = 0.031, respectively). Complications occurred in 5.98 % (N = 17) of cases.

Conclusion: Cryobiopsy demonstrates a statistically higher diagnostic yield and sensitivity for malignancy compared to FNA. Remarkably, FNA showed reduced diagnostic odds in PPN < 15 mm. ssRAB with cryobiopsy could enhance PPN diagnostic yield, leading to earlier lung cancer diagnosis and improve long-term survival rates.